[NCLUG] SCSI disk spares management utility

[Sean Reifschneider]

On Tue, Apr 15, 2003 at 10:15:48AM -0600, John L. Bass wrote:
>quietly leaves the customer with corrupt files. For critical business
>applications this is VERY WRONG.  This "may" work fine for most low end

For critical business applications, you shouldn't rely on the storage
sub-system being perfect.  For example, one of our image archive
solutions includes, effectively, tripwire in it.  The images that
haven't been archived off to other media are daily checked for
corruption and an alert is generated if any on-disc data doesn't match
the appropriate hashes.

This definitely gives you an early opportunity to discover if files have
gotten corrupted and pull them from backups, without having to follow
drive re-mapping and track down what file(s) the block correesponds to.

When I've worked with "critical business applications", we've usually
just let the read error take the drive off-line, then reconstructed that
data from the redundant data, relying on the bad block mapping to make
the disc happy again.  Of course, this would usually be after pumping a
bunch of data to/from the drive...

I've never been in, or even heard of, an environment where they specified
that you could be fired for not doing low-level analysis of a drive
read failure...  This includes working with healthcare data and billing
data.

Sean
-- 
 We are all in the gutter, but some of us are looking at the stars.
                 -- Oscar Wilde
Sean Reifschneider, Inimitably Superfluous <jafo at tummy.com>
tummy.com, ltd. - Linux Consulting since 1995.  Qmail, Python, SysAdmin